1. Field of the Invention
The present invention relates to steerable surgical cutting instruments and, more particularly, to articulating mechanisms for steerable surgical cutting instruments powered by powered surgical handpieces to cut anatomical tissue.
2. Brief Discussion of the Related Art
A typical surgical cutting instrument powered by a powered surgical handpiece includes elongate inner and outer members having inner and outer hubs, respectively, releasably coupled with the powered surgical handpiece. The handpiece typically rotates the inner member relative to the outer member to effect cutting of anatomical tissue at a distal end of the instrument. Cutting of the anatomical tissue is typically accomplished with a distal end of the inner member, which is exposed from an open distal end of the outer member. In order to better access anatomical tissue to be cut, it is desirable in many circumstances for the outer and inner members to be bendable or steerable to selectively adjust the position of the instrument distal end.
Bending or steering of outer and inner members of a surgical cutting instrument has been accomplished with the use of wires or cables as represented by U.S. Pat. No. 5,938,678 to Zirps et al, U.S. Pat. No. 5,899,914 to Zirps et al, U.S. Pat. No. 5,885,288 to Aust et al, U.S. Pat. No. 5,669,926 to Aust et al, U.S. Pat. No. 5,618,294 to Aust et al, U.S. Pat. No. 5,540,706 to Aust et al, and U.S. Pat. No. 5,454,827 to Aust et al.
In the area of steerable surgical cutting instruments and, in particular, steerable shavers, powered by powered surgical handpieces, there are unfulfilled needs. A need exists for an articulating mechanism that guides the wires used to impart bending to the outer and inner members, facilitates movement of the wires to effect bending and release of the outer and inner members, and resists kinking of the wires during actuation and release. There is a further need for an articulating mechanism including an outer hub that allows for mounting of a wire guide and a pivotable actuator used to move the actuating wires. Also, there is a need for an outer hub providing guidance for the wires, limits on pivotal movement of the actuator and/or proper positioning of the wire guide. A need further exists for an articulating mechanism including housing sections forming a housing that shields the working parts of the articulating mechanism, facilitates proper assembly and cooperates with the actuator to lock the actuator in a pivoted position.
Accordingly, it is a primary object of the present invention to fulfill unmet needs in the field of steerable surgical cutting instruments powered by powered surgical handpieces.
Another object of the present invention is to provide an articulating mechanism for a steerable shaver powered by a powered surgical handpiece.
A further object of the present invention is to pivotably mount an actuator on an outer hub of a steerable surgical cutting instrument for effecting movement of actuating wires to bend outer and inner members of the instrument in response to pivotable movement of the actuator, with the actuator being mounted distally of a powered surgical handpiece to which the outer hub is releasably connectible.
An additional object of the present invention is to guide the wires of a steerable surgical cutting instrument, for attachment to a pivotable actuator, via a wire guide disposed on an outer member of the instrument distally of an outer hub secured to a proximal end of the outer member.
The present invention also has as an object to facilitate assembly of an articulating mechanism for a steerable surgical cutting instrument.
It is a further object of the present invention to shield the working parts of an articulating mechanism for a steerable suction cutting instrument with a housing formed of housing sections assembled over an outer hub of the instrument distally of a powered surgical handpiece used to power the instrument to cut anatomical tissue.
Some of the advantages of the present invention are that the outer hub has structure for mounting the wire guide thereto, the wire guide guides actuating and return wires of the instrument, structure on the outer hub guides the return wires from the wire guide for attachment to the actuator, pivotal movement of the actuator is limited or controlled via structure on the outer hub, the outer hub has a port for irrigation through the instrument, the wire guide has an inner surface configured to guide the wires and keep them from kinking during actuation and release, the wire guide locks onto the outer hub to maintain proper location, movement of the wires is eased, attachment of the wires to the actuator is facilitated by structure of the actuator, the pivot point for the actuator provides the necessary travel for the wires, a locking member on the actuator is lockingly engageable with a plurality of detents on the housing to lock the actuator in a selected one of a plurality of pivoted positions, the locking member can be removed if locking is not desired, the locking member is capable of being easily released from the detents to effect release of the outer and inner members of the instrument, the housing covers the working parts of the articulating mechanism for safety, the housing sections can be ultrasonically welded to insure durability, and the housing sections are provided with locating features to facilitate assembly.
These and other objects, advantages and benefits are achieved with the present invention as generally characterized in an articulating mechanism incorporated in a steerable surgical cutting instrument, such as a steerable shaver, powered by a steerable surgical handpiece. A steerable surgical cutting instrument including the articulating mechanism of the present invention comprises a bendable outer tubular member having open distal and proximal ends, a bendable inner member disposed in the outer tubular member and having a distal end exposed from the distal end of the outer tubular member and having a proximal end, at least one actuating wire extending proximally from the outer tubular member to effect bending of the outer and inner members when the actuating wire is pulled in a proximal direction, an outer hub secured to the proximal end of the outer tubular member and an inner hub secured to the proximal end of the inner member. The outer hub has a passage therethrough receiving the inner member with the inner hub disposed proximally of the outer hub. The outer and inner hubs are releasably connectible to a powered surgical handpiece used to rotate the inner member within the outer tubular member to cut anatomical tissue with the distal end of the inner member. In a preferred embodiment, a pair of actuating wires extend proximally from one side of the outer tubular member and a pair of return wires extend proximally from an opposite side of the outer tubular member. The return wires effect straightening of the outer and inner members when the actuating wires are not pulled proximally. The articulating mechanism includes the outer hub, a wire guide disposed on the outer tubular member, an actuator to which the actuating and return wires are attached and a housing mounted on the outer hub distally of the powered surgical handpiece. The actuator is pivotally mounted on the outer hub and has a rest position wherein the outer and inner members are straight. The actuator is pivotably or rotatably movable from the rest position to a pivoted position to pull the actuating wires proximally to effect bending of the outer and inner members. The wire guide has a lumen through which the outer tubular member passes, and an inner surface of the wire guide is configured to guide the actuating and return wires to extend proximally from the wire guide for attachment to the actuator. The wire guide is assembled to engagement members on the outer hub and is held and located by structure on the housing. The outer hub has travel stops cooperating with the actuator to limit or control pivotable or rotational movement of the actuator. The outer hub has guide structure thereon guiding the return wires extending from the wire guide for attachment to the actuator. The housing has detents cooperating with a locking member on the actuator to releasably lock the actuator in various pivoted positions. The outer hub includes an irrigation port for the instrument by which an irrigating fluid can be introduced between the inner and outer members.
Inasmuch as the present invention is subject to many variations, modifications and changes in detail, it is intended that all subject matter discussed above or shown in the accompanying drawings be interpreted as illustrative only and not be taken in a limiting sense.